拟南芥(Arabidopsis thaliana)中自主通路成员FLOWERING LOCUS VE(FVE)主要通过表观遗传学机制抑制其下游开花抑制子FLOWERING LOCUS C(FLC)的表达从而促进开花,但有研究发现蒺藜苜蓿(Medicago truncatula)中没有FLC的同源基因,因此,蒺...拟南芥(Arabidopsis thaliana)中自主通路成员FLOWERING LOCUS VE(FVE)主要通过表观遗传学机制抑制其下游开花抑制子FLOWERING LOCUS C(FLC)的表达从而促进开花,但有研究发现蒺藜苜蓿(Medicago truncatula)中没有FLC的同源基因,因此,蒺藜苜蓿中FVE同源基因调控开花时间的分子作用机理还有待研究。通过生物信息学方法在蒺藜苜蓿中筛选到2个拟南芥FVE的同源蛋白,将其分别命名为MtFVEa和MtFVEb。经氨基酸序列比对发现,2个蛋白均具有典型的WD40蛋白结合结构域。随后通过qRT-PCR和半定量RT-PCR检测MtFVEa和MtFVEb基因组织表达特异性,发现2个基因在花和营养生长期的茎尖具有较高水平的表达。经酵母双杂实验进一步分析发现,MtFVEa蛋白与MtFLD [拟南芥FLOWERING LOCUS D(FLD)的同源蛋白]和MtHDA6 [拟南芥histone deacetylase 6(HDA6)的同源蛋白]均发生蛋白互作,表明MtFVE可能同样形成FVE-FLD-HDA6三元复合体参与蒺藜苜蓿开花调控。研究结果为进一步探索蒺藜苜蓿MtFVE基因的功能提供了研究思路和理论支持。展开更多
植物自主开花途径花发育基因FVE对植物营养生长向生殖生长的转变起重要的调控作用。为了进一步研究该基因在小麦中的调控功能,利用小麦基因组数据和二穗短柄草基因组数据,通过RT-PCR和PCR技术对小麦花发育基因FVE的DNA序列和cDNA序列进...植物自主开花途径花发育基因FVE对植物营养生长向生殖生长的转变起重要的调控作用。为了进一步研究该基因在小麦中的调控功能,利用小麦基因组数据和二穗短柄草基因组数据,通过RT-PCR和PCR技术对小麦花发育基因FVE的DNA序列和cDNA序列进行了克隆和序列分析,分别获得了7 034bp(TriFVE1,Gene Bank JQ317687)和6 910bp(TriFVE2,Gene Bank JQ317688)的两个FVE基因序列。基因结构分析表明,FVE基因由15个外显子和14个内含子组成,TriFVE1和TriFVE2基因的内含子序列存在大片段的插入/缺失,同源性仅为79.87%。TriFVE1和TriFVE2的cDNA编码区序列均为1 368bp,存在4个SNP位点,编码455个氨基酸的FVE蛋白序列完全一致。利用"中国春"和21个缺四体将TriFVE1和TriFVE2分别定位于小麦3A和3D染色体上。利用实时荧光定量PCR(qRT-PCR)技术分析了FVE基因在单棱期、二棱期和穗分化时期的小麦茎尖组织表达模式,发现二棱期和穗分化期TriFVE的转录水平显著高于单棱期,表明FVE在小麦花发育由营养生长到生殖生长过程中起重要作用。基于FVE蛋白序列的系统进化树分析表明,苔藓植物、单子叶和双子叶植物被明显分为不同类群,该基因随着物种的进化而进化,可以为研究植物分子进化关系提供参考。展开更多
Background:The current mainstay for control/elimination of onchocerciasis and soil-transmitted helminthiasis(STH)relies on ivermectin-and mebendazole/albendazole-based preventive chemotherapies.However,children under ...Background:The current mainstay for control/elimination of onchocerciasis and soil-transmitted helminthiasis(STH)relies on ivermectin-and mebendazole/albendazole-based preventive chemotherapies.However,children under fve years of age have been excluded in both research activities and control programs,because they were believed to have insignifcant infection rates.There is therefore a need for up-to-date knowledge on the prevalence and inten‑sity of STH and onchocerciasis infections in this age group.This study aimed at assessing the rates and intensities of onchocerciasis and STH infections in children under fve years of age who are excluded from ivermectin-or mebenda‑zole/albendazole-based preventive chemotherapies.Methods:A series of cross-sectional surveys was conducted in four Health Districts in the Centre and Littoral Regions of Cameroon between 2018 and 2019.All subjects aged 2 to 4 years,were screened for prevalence(or infection rate)and intensity[number of eggs per gram of stool(epg)or number of microflariae per skin snip(mf/ss)]of STH and onchocerciasis infections respectively using the Kato-Katz and skin snip methodologies.Chi-square and the nonparametric tests(Mann Whitney and Kruskal Wallis)were used to compare infection rates and intensities of infections between Health Districts and genders,respectively.Results:A total of 421 children were enrolled in this study.The overall prevalence of onchocerciasis was 6.6%[95% confdence interval(CI):4.3‒9.9],ranging from 3.6%(in the Ntui Health District)to 12.2%(in the Bafa Health District).The intensity of infection ranged from 0.5 to 46 microflariae per skin snip[median:5;interquartile range(IQR):2.25‒8.5].The overall prevalence of STH was 9.6%(95%CI:6.5‒13.9),with a high infection rate(29.6%)in the Akonolinga Health District.Two STH species(Ascaris lumbricoides and Trichuris trichiura)were found among infected individuals.The median intensities of STH infections were 1,992 epg(IQR:210‒28,704)and 96 epg(IQR:48‒168)for A.lumbricoides and T.trichiura,respectively.Conclusions:This study reveals that children<5 years of age are highly infected with STH and onchocerciasis,and could contribute to the spread of these diseases,perpetuating a vicious circle of transmission and hampering elimi‑nation eforts.These fndings reveal the urgent need to provide(or scale)treatments(likely pediatric formulations)to these preschool-aged children,especially in areas of high transmission,to accelerate eforts to reach WHO 2030 target.展开更多
目的对金针菇免疫调节蛋白(fungal immunomodulatory protein fromflammulina velutipes,FIP-fve)基因进行原核表达及活性测定。方法通过RT-PCR得到FIP-fve,构建pUC19-FIP-fve,和表达质粒pET30-FIP-fve,转化大肠杆菌DE3(BL21),经IPTG诱...目的对金针菇免疫调节蛋白(fungal immunomodulatory protein fromflammulina velutipes,FIP-fve)基因进行原核表达及活性测定。方法通过RT-PCR得到FIP-fve,构建pUC19-FIP-fve,和表达质粒pET30-FIP-fve,转化大肠杆菌DE3(BL21),经IPTG诱导,表达产物纯化后进行活性试验。结果该基因在DE3(BL21)中获得了大量表达。表达产物能促进巨噬细胞吞噬功能(P<0.01)、明显增加小鼠血清中IFN-γ的含量(P<0.01)及抑制小鼠移植性S180肉瘤的生长,其抑瘤率分别为31.84%(P<0.05)和36.04%(P<0.05)。结论表达蛋白具有活性,这对于将其开发为免疫调节、抗过敏、抗肿瘤新药具有重要意义。展开更多
This paper is concerned with establishing a reduced-order extrapolating fi- nite volume element （FVE） format based on proper orthogonal decomposition （POD） for two-dimensional （2D） hyperbolic equations. For this...This paper is concerned with establishing a reduced-order extrapolating fi- nite volume element （FVE） format based on proper orthogonal decomposition （POD） for two-dimensional （2D） hyperbolic equations. For this purpose, a semi discrete variational format relative time and a fully discrete FVE format for the 2D hyperbolic equations are built, and a set of snapshots from the very few FVE solutions are extracted on the first very short time interval. Then, the POD basis from the snapshots is formulated, and the reduced-order POD extrapolating FVE format containing very few degrees of freedom but holding sufficiently high accuracy is built. Next, the error estimates of the reduced-order solutions and the algorithm procedure for solving the reduced-order for- mat are furnished. Finally, a numerical example is shown to confirm the correctness of theoretical conclusions. This means that the format is efficient and feasible to solve the 2D hyperbolic equations.展开更多
This paper seeks to identify the minimal restrictions that need to be placed on the naive comprehension principle to avoid inconsistency in set theory. Analysis of the logical antinomies shows that at the root of inco...This paper seeks to identify the minimal restrictions that need to be placed on the naive comprehension principle to avoid inconsistency in set theory. Analysis of the logical antinomies shows that at the root of inconsistency in naive set theory are certain ＂self contradictory＂ predicate functions in extensional set descriptions containing the matrix ＂-（x∈y）＂ （or ＂-（x∈x）＂） rather than ＂size,＂ vicious circularity, or self-reference. A reformed set comprehension system is proposed that excludes extensional set descriptions that conform to the formula, （Vx） （Зy） （x∈y →P （x）） （3u） （u∈y→（u∈y））, from comprehension and otherwise preserves the ontology of na＇fve set theory. This reform avoids the paradoxes by scrutiny of a set＇s description without recourse to type or other constructivist limitations on self-membership and has the most liberal rules for set formation conceivable including self-membership. The intuitive appeal for such an approach is compelling because as a revision of na＇fve set theory, it allows all possible set descriptions that do not lead to inconsistency.展开更多
文摘拟南芥(Arabidopsis thaliana)中自主通路成员FLOWERING LOCUS VE(FVE)主要通过表观遗传学机制抑制其下游开花抑制子FLOWERING LOCUS C(FLC)的表达从而促进开花,但有研究发现蒺藜苜蓿(Medicago truncatula)中没有FLC的同源基因,因此,蒺藜苜蓿中FVE同源基因调控开花时间的分子作用机理还有待研究。通过生物信息学方法在蒺藜苜蓿中筛选到2个拟南芥FVE的同源蛋白,将其分别命名为MtFVEa和MtFVEb。经氨基酸序列比对发现,2个蛋白均具有典型的WD40蛋白结合结构域。随后通过qRT-PCR和半定量RT-PCR检测MtFVEa和MtFVEb基因组织表达特异性,发现2个基因在花和营养生长期的茎尖具有较高水平的表达。经酵母双杂实验进一步分析发现,MtFVEa蛋白与MtFLD [拟南芥FLOWERING LOCUS D(FLD)的同源蛋白]和MtHDA6 [拟南芥histone deacetylase 6(HDA6)的同源蛋白]均发生蛋白互作,表明MtFVE可能同样形成FVE-FLD-HDA6三元复合体参与蒺藜苜蓿开花调控。研究结果为进一步探索蒺藜苜蓿MtFVE基因的功能提供了研究思路和理论支持。
文摘植物自主开花途径花发育基因FVE对植物营养生长向生殖生长的转变起重要的调控作用。为了进一步研究该基因在小麦中的调控功能,利用小麦基因组数据和二穗短柄草基因组数据,通过RT-PCR和PCR技术对小麦花发育基因FVE的DNA序列和cDNA序列进行了克隆和序列分析,分别获得了7 034bp(TriFVE1,Gene Bank JQ317687)和6 910bp(TriFVE2,Gene Bank JQ317688)的两个FVE基因序列。基因结构分析表明,FVE基因由15个外显子和14个内含子组成,TriFVE1和TriFVE2基因的内含子序列存在大片段的插入/缺失,同源性仅为79.87%。TriFVE1和TriFVE2的cDNA编码区序列均为1 368bp,存在4个SNP位点,编码455个氨基酸的FVE蛋白序列完全一致。利用"中国春"和21个缺四体将TriFVE1和TriFVE2分别定位于小麦3A和3D染色体上。利用实时荧光定量PCR(qRT-PCR)技术分析了FVE基因在单棱期、二棱期和穗分化时期的小麦茎尖组织表达模式,发现二棱期和穗分化期TriFVE的转录水平显著高于单棱期,表明FVE在小麦花发育由营养生长到生殖生长过程中起重要作用。基于FVE蛋白序列的系统进化树分析表明,苔藓植物、单子叶和双子叶植物被明显分为不同类群,该基因随着物种的进化而进化,可以为研究植物分子进化关系提供参考。
文摘Background:The current mainstay for control/elimination of onchocerciasis and soil-transmitted helminthiasis(STH)relies on ivermectin-and mebendazole/albendazole-based preventive chemotherapies.However,children under fve years of age have been excluded in both research activities and control programs,because they were believed to have insignifcant infection rates.There is therefore a need for up-to-date knowledge on the prevalence and inten‑sity of STH and onchocerciasis infections in this age group.This study aimed at assessing the rates and intensities of onchocerciasis and STH infections in children under fve years of age who are excluded from ivermectin-or mebenda‑zole/albendazole-based preventive chemotherapies.Methods:A series of cross-sectional surveys was conducted in four Health Districts in the Centre and Littoral Regions of Cameroon between 2018 and 2019.All subjects aged 2 to 4 years,were screened for prevalence(or infection rate)and intensity[number of eggs per gram of stool(epg)or number of microflariae per skin snip(mf/ss)]of STH and onchocerciasis infections respectively using the Kato-Katz and skin snip methodologies.Chi-square and the nonparametric tests(Mann Whitney and Kruskal Wallis)were used to compare infection rates and intensities of infections between Health Districts and genders,respectively.Results:A total of 421 children were enrolled in this study.The overall prevalence of onchocerciasis was 6.6%[95% confdence interval(CI):4.3‒9.9],ranging from 3.6%(in the Ntui Health District)to 12.2%(in the Bafa Health District).The intensity of infection ranged from 0.5 to 46 microflariae per skin snip[median:5;interquartile range(IQR):2.25‒8.5].The overall prevalence of STH was 9.6%(95%CI:6.5‒13.9),with a high infection rate(29.6%)in the Akonolinga Health District.Two STH species(Ascaris lumbricoides and Trichuris trichiura)were found among infected individuals.The median intensities of STH infections were 1,992 epg(IQR:210‒28,704)and 96 epg(IQR:48‒168)for A.lumbricoides and T.trichiura,respectively.Conclusions:This study reveals that children<5 years of age are highly infected with STH and onchocerciasis,and could contribute to the spread of these diseases,perpetuating a vicious circle of transmission and hampering elimi‑nation eforts.These fndings reveal the urgent need to provide(or scale)treatments(likely pediatric formulations)to these preschool-aged children,especially in areas of high transmission,to accelerate eforts to reach WHO 2030 target.
文摘目的对金针菇免疫调节蛋白(fungal immunomodulatory protein fromflammulina velutipes,FIP-fve)基因进行原核表达及活性测定。方法通过RT-PCR得到FIP-fve,构建pUC19-FIP-fve,和表达质粒pET30-FIP-fve,转化大肠杆菌DE3(BL21),经IPTG诱导,表达产物纯化后进行活性试验。结果该基因在DE3(BL21)中获得了大量表达。表达产物能促进巨噬细胞吞噬功能(P<0.01)、明显增加小鼠血清中IFN-γ的含量(P<0.01)及抑制小鼠移植性S180肉瘤的生长,其抑瘤率分别为31.84%(P<0.05)和36.04%(P<0.05)。结论表达蛋白具有活性,这对于将其开发为免疫调节、抗过敏、抗肿瘤新药具有重要意义。
基金Project supported by the National Natural Science Foundation of China(Nos.11271127 and11671106)
文摘This paper is concerned with establishing a reduced-order extrapolating fi- nite volume element （FVE） format based on proper orthogonal decomposition （POD） for two-dimensional （2D） hyperbolic equations. For this purpose, a semi discrete variational format relative time and a fully discrete FVE format for the 2D hyperbolic equations are built, and a set of snapshots from the very few FVE solutions are extracted on the first very short time interval. Then, the POD basis from the snapshots is formulated, and the reduced-order POD extrapolating FVE format containing very few degrees of freedom but holding sufficiently high accuracy is built. Next, the error estimates of the reduced-order solutions and the algorithm procedure for solving the reduced-order for- mat are furnished. Finally, a numerical example is shown to confirm the correctness of theoretical conclusions. This means that the format is efficient and feasible to solve the 2D hyperbolic equations.
文摘This paper seeks to identify the minimal restrictions that need to be placed on the naive comprehension principle to avoid inconsistency in set theory. Analysis of the logical antinomies shows that at the root of inconsistency in naive set theory are certain ＂self contradictory＂ predicate functions in extensional set descriptions containing the matrix ＂-（x∈y）＂ （or ＂-（x∈x）＂） rather than ＂size,＂ vicious circularity, or self-reference. A reformed set comprehension system is proposed that excludes extensional set descriptions that conform to the formula, （Vx） （Зy） （x∈y →P （x）） （3u） （u∈y→（u∈y））, from comprehension and otherwise preserves the ontology of na＇fve set theory. This reform avoids the paradoxes by scrutiny of a set＇s description without recourse to type or other constructivist limitations on self-membership and has the most liberal rules for set formation conceivable including self-membership. The intuitive appeal for such an approach is compelling because as a revision of na＇fve set theory, it allows all possible set descriptions that do not lead to inconsistency.
